Method
The nth term is aₙ = a₁ + (n − 1)d. The sum of the first n terms is Sₙ = n(a₁ + aₙ) ÷ 2.
Example
For first term 3 and common difference 5, the tenth term is 48 and the first five terms are 3, 8, 13, 18, 23.
Limits
Check inputs and units. Important academic, financial or professional decisions should be confirmed against an appropriate source.
Common questions
Can this find missing arithmetic sequence terms?
Enter the first term, common difference and term position to calculate that term and preview the sequence.
How is the nth term of an arithmetic sequence calculated?
Use aₙ = a₁ + (n − 1)d, where a₁ is the first term and d is the common difference.
What does the arithmetic sequence calculator calculate?
Find the nth term, first terms and sum of an arithmetic sequence.
Does this arithmetic sequence calculator show its method?
Yes. The result includes the central formula or working needed to check the answer.
Are my values uploaded?
No. The calculation runs in this browser and does not require an account.